GEMS can use one powerful workstation to simulate a complete car model in a reasonable time. GEMS delete any specific pieces in the model, add thickness to any parts, and generate a conformal antenna or array on the top roof or windshield.

The original car model is in AutoCAD format, it is difficult for most EM simulation software to import this car model. However, GEMS can import this model in 1 minute. Using the surface mesh, GEMS can accurately calculate the surface current distribution on the car body. Since the conformal surface is used in GEMS, a regular laptop can easily display the conformal current distribution on the entire car body.

In the simulation, if the car body is infinitely thin PEC material, GEMS can guarantee the continuous surface without power leaking from one side to another side even if you can use coarse mesh. The fine structure inside car model is the thickness of front and rear windshields and windows, which require the fine mesh to describe the field variation inside the glass.

The conformal antenna can be imported from the CAD file or generated in the GEMS interface. The antenna may be slanted related to the coordinate system, therefore, we need to use the small cell size to describe the fine antenna structure.

In any case, the antenna feed gap should be along the axis to use the correct excitation and obtain the correct output parameters.